Desalinating Water Is Becoming "Absurdly Cheap" | Hacker News Reader

Desalinating Water Is Becoming "Absurdly Cheap"

humanprogress.org

47 pointsjupp0r52 comments

Some quick googling says that the average person in the U.S. uses about 100 gallons per day directly, and about 1,000 gallons per day total (including all usage). That means the U.S. could replace all water usage for less than $1 billion per day.

In particular, that means the U.S. could solve the Colorado river allocation issue for about $10 billion per year.

which would likely be more than all the Colorado river water is going for now? see https://news.ycombinator.com/item?id=40881819

EDIT: redoing that calculation for 15'000'000 acre-feet/yr (7,5 upper + 7,5 lower) yields only 3,75 billion USD/yr.

EDIT2: also neglected: that only one of the seven states in the compact has easy access to salinated water.

That may be, but the fact remains that the Colorado is over-allocated by some ridiculous amount, and the states and Mexico are arguing over it. Some non-zero amount is spent making e.g. Las Vegas and Phoenix more water-efficient to help alleviate the issue.

Even if $20 billion per year, it is worth it. It could generate a lot of revenue for people and industry. Probably more than the cost of maintenance of these plants.

But the Federal Gov, when controlled by a specific party, does not want to pay for anything will help society.

Does this account for all water usage or only domestic water use?

Most of the biggest water users are agricultural or industrial.

Domestic seems to be about 100 gallons per day, per capita 1,000.

There is an environmental cost to this though, that extra salt is probably just dumped back in the ocean.

Obviously that's not a problem in general: the salt comes from the ocean, and the salt as well as the fresh water extracted go back to the ocean just by different paths.

But the salt (in the form of brine, as I understand it) is generally localized, and thus can be an environmental issue that needs to be addressed.

There's no way a human directly uses 100 gallons a day without changing the definition of "directly"...

I'd interpret "directly" as water that was consumed, touched, or seen. Doesn't seem unreasonable to me between bathing, toilet use, washing, food prep, and drinking.

When I think of "directly", it's not just drinking, but all water usage under your direct control. That includes cooking, cleaning, bathing, flushing, watering your plants, etc. Basically everything that flows through your home. It would not include things like the water used to grow the food you buy, to water the grass in your local golf course, etc.

I'm on the board of a small California water company with ~750 customers. Our average household usage is ~100 gallons per day, a little more in the summer and a little less in the winter. Most households here are 1-2 people, mostly people over 60, and very few children. This is a forested area in the mountains (4,500 foot elevation) with no agriculture. I'm only aware of one lawn and no swimming pools. We get a lot or precipitation, so most plants and trees around here do not get watered. All that to say that we're likely lighter usage than a lot of areas, especially in California. So 100 gallons per person per day being used directly is probably a reasonable order of magnitude guess.

Wow. That obviously is shocking to me ...

Where does all the brine go currently? The countries most dependent on desalination currently at least seem to have plenty of desert space available to dump it, but I do wonder if it might reach volumes that are difficult to manage once desalination becomes more widespread.

Though perhaps dumping it back into the ocean is the correct thing to do, because the extracted fresh water will eventually also stream back into the ocean via the normal water cycle.

I seem to remember reading that dumping the brine byproduct from desalination in the ocean can screw up marine life. I don't have a reference ready, will look for one. I guess there might be a "right" way of dumping brine in the ocean without harming marine life, but I have no idea what that would be.

Plan it to be combined with waste water treatment or other cooling water from power plants to dilute it, or disperse it over a larger area. It goes into the ocean currently.

You can also dilute it with lots of seawater

It would cause areas of higher salt concentrations where it is dumped. They only way to not cause this (for large volumes of brine) would be to dilute it first and of course that defeats the purpose of salination.

You can dilute with treated waste water.

Pump it through pipe a few miles off coast?

It still doesn’t solve the issue.

Two of the major problems is brine doesn’t homogenize well and its denser than seawater. You end up brine that settles into ever nook and cranny on the sea floor without mixing back into the ocean.

Probably a solvable problem, but not something that has a good solution right now.

Pump it through pipes with holes in it, so that it leaks n% brine every x% miles. This assures dilution of the brine.

If you dump it into an evaporation pond, you can pick up all the minerals and metals left behind such as lithium.

good. we got the minerals.

but now where do we put all of the salt?

Send it to Northern countries for road deicing?

They need less salt due to there being less ice due to global warming.

I worry about the waste which can destroy habitats and soil forever. I'm not a scientist, but I know what happens if someone pours salt on a garden, or a water habitat becomes too salty. Not good. Cheap is great, but something has to be done with the waste so that it doesn't cause more environmental damage.

https://news.sky.com/story/woman-whose-allotment-was-sabotag...

https://en.wikipedia.org/wiki/Salton_Sea

Desalination is a blessing but it also increases the dependence of the population on technical infra for daily survival. If something were to happen to the desalination plants, that's no water, immediately (in the UAE case, for example).

The same is true about electricity or gasoline. Once the pumps stop working and the trucks stop supplying the supermarkets, you have maybe two weeks.

We could decrease our dependence our electricity and gasoline too. Who knows, it might even be beneficial for the environment.

If the municipal pumps stop there will be 20 mins of water or so from the gravity header tank. No difference.

Government tank trucks will shortly begin distributing water. It might not be enough for a good wash, but nobody will be dying of thirst.

You can't start eating people when the trail head's in sight.

You gotta give it some space. Let it breathe.

There's 70 plants, it's unlikely something would happen to all of them at the same time.

Except something like an EMP or other large scale breakdown of infrastructure.

Reducing dependence on technical infra doesn't always work out either; the story of the https://en.wikipedia.org/wiki/Lykov_family suggests that for any long-term attempts at autarky, N should be >6. (how much greater?)

The pipes themselves are the vulnerable infrastructure. Calgary just had an emergency situation for a few weeks because of a broken pipe.

Simply not true for the UAE with numerous dams and they are also refilling aquifers to store water.

Well... The issue is that produced water is not much healthy to drink, not "salty" but "near salty". The "full desalination" it's much more expensive and limited in output, also involving washed clean sand to produce good mineral water...

“HumanProgress.org is a project of the Cato Institute“

Good catch. From their website "Promoting an American public policy based on individual liberty, limited government, free markets and peaceful international relations."

"Absurdly Cheap" compared with what?

They give desal cost (not final price!) as USD 0,75 / m3.

USD 250 / acre-foot for delivered water in the San Joaquin Valley is USD 0,20 / m3.

So I'll grant them "cheap", but at more than 3x, defo not "absurdly" so.

https://water.ca.gov/-/media/DWR-Website/Web-Pages/News/File...

Absurdly cheap to a billionaire who's never given AF about ordinary, let alone poor, people.

This is still about 1/3 the price of city water is lots of the EU. People make less than half that of Americans and people manage. People will just use less damned water, which is a good thing.

It _should_ be stupidly expensive to keep your yard green in Tx in the summer. Americans are living with artificially low prices for so many things.

There is no lack of natural drinkable water and never will be. But it's an important agenda to convince people that there is. Why? I don't know, probably for power over other people.

I'm from a pace where there's an absurd amount of naturally occurring clean water and even there they are pushing this false agenda.

If people decide to live where there is no water, that's not a global problem, that's a people problem.

The problem is people can simply up and migrate to places with lots of space, drinking water, because of the way the globe is going these days.

> Water flows uphill towards money —old Californian proverb

see https://en.wikipedia.org/wiki/California_water_wars

You've missed the plot.

People have always had to live where there is access to water.

It's that the water where people decided to live decades or even centuries ago is starting to disappear due to a variety of factors (population growth, overuse, natural cycles, and yes, climate change).

This then leads to a variety of short term instability and social issues like mass migrations and conflict because humans need water.

Water is in no way disappearing in the place where I'm from, yet there are media and political campaigns about coming water shortages there. Even though it's geologically impossible. It's comparable to creating a big scare about tropical diseases in some place like Iceland. And everybody has to pretend that all science and evidence in front of your eyes is moot.

Has the human mind deteriorated now to the extent that people cannot understand that some issues are local? I am reminded of the Soviet days, when they changed farming techniques with disastrous results, because they had "new knowledge". The scientific knowledge in question was "I god damned said so" from the rulers. Anybody who disagrees is a traitor, sent into exile, or down voted by hackers.

    Water is in no way disappearing in the place where I'm from, yet there are media and political campaigns about coming water shortages there.

Depending on where you are, there is likely a delta between how much water is typically used and how much is being replenished in reservoirs. So while it's not going to immediately disappear, the rate of replacement is likely lower and unsustainable over a given period of time without corrective action.

One aspect to consider is that abnormal climate events are now harder to predict because shifts in decades (in some cases, centuries) of stable weather patterns. So extreme rains and snows are a good example where models show a trend towards loss of reservoirs, but one event can throw the model off. A good example is the recent snowfalls in Big Sur[0] and then heavy flooding events the following spring [1]

[0] https://www.independent.com/2023/03/21/big-sur-in-the-snow/

[1] https://www.ktvu.com/news/big-sur-highway-1-temporary-fix-pl...

If your part of the world is constantly under drought advisories, I would suggest that rather than going by your "gut" or going by news media, go to the source and find the academic and scientific papers relevant to your region of the world and see why some scientists might be raising the alarm about water levels. More than likely, you'll find that there's solid evidence that the rate of fresh water replenishment is in a negative trajectory.

There's never been a drought there historically. The geological and geographical realities simply don't permit it. Maybe if the population suddenly increased by a hundred times over, there could be some water issues. Not for a lack of water, but lack of infrastructure. The government/media (they're one and the same there) just decided a couple of years ago that water access was a huge problem. There are no academic or scientific papers claiming any risk of water shortage, because there is no scientific basis for it.

So I'm curious as to their purpose. Sure, the politicians can hire some friends and relatives to well paid government jobs to plan for a drought that will never come. The media can keep a percentage of their readers in the state of anxiety that they love. And probably it can help in having a part of the population take their minds of real problems that would require real solutions. But those reasons sound kind of meagre. Is it a bid to nationalize and privatize the water supply for further control and profit? Could be.

> More than likely, you'll find that there's solid evidence that the rate of fresh water replenishment is in a negative trajectory.

You seem to blindly assume that any government is completely right in everything they do and say. If I wrote that there was a huge drought in my region and the government denies it, then you would argue here that the government is right and the cattle dying of dehydration are just reactionaries.

What's your water source?

Lots of precipitation, ground water and gigantic freshwater lakes.

Reply on news.ycombinator.com